Hearing aid accessories for adults: The remote FM microphone
Hearing aid accessories for adults: The remote FM microphone
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DOI：
10.1097/01.aud.0000111260.46595.ec
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发表时间：
2004-02-01
期刊：
影响因子：
3.7
通讯作者：
Boothroyd, A
中科院分区：
文献类型：
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作者：
Boothroyd, A
目标：主要目标是确定远程调频麦克风作为助听器配件的优点和局限性。第二个目标是使用源自发音指数理论的方法，确定听力损失成年人在安静和噪音情况下辅助和调频辅助言语感知的预测因素。设计：12 名年龄在 52 至 85 岁之间的轻度至重度听力损失成年人佩戴耳后调频助听器并使用至少 2 周。在试用期前后，在三种条件下在多个语音级别上测量音素识别：在安静环境中辅助、在频谱匹配噪声中辅助以及在噪声中辅助调频。试用期前提供了一次咨询、指导和演示。在试验期结束时通过问卷调查评估感知效益。测量和感知的益处与年龄和纯音阈值相关。结果：噪声中的 FM 辅助音素识别相当于安静中的辅助音素识别。在假设清晰度指数（AI）随着高频阈值的增加而以每 dB 约 1 个百分点的速率下降的模型下，通过 2 kHz 和 4 kHz 的平均纯音阈值可以很好地预测两者。在假设信噪比为 0 dB 的模型下，可以通过相同的平均阈值很好地预测噪声中的辅助音素识别，从而将清晰度指数降低到安静情况下的三分之一。无论是在远处、在安静还是在噪音中，一个说话者的平均感知益处最高。对于多个谈话者（系统预计无效）和一个安静的谈话者（系统应该是不必要的）来说，它是最低的。年龄较大的受试者和在噪音中辅助识别能力较差的受试者往往表现出较低的感知益处。许多受试者报告说该系统在降低背景噪音方面无效。这一发现归因于在通过助听器和调频麦克风调整相对增益时使用了“相等增益”标准。对于许多受试者来说，单一的审前咨询、指导和演示显然是不够的。没有人表示有意购买 FM 系统。结论：远程 FM 麦克风在减少距离和噪音对单个讲话者的负面影响方面的预期优势可以在实验室和现场条件下得到证明。听力损失、噪音和调频辅助对辅助音素识别的影响可以通过清晰度指数理论派生的方法很好地预测。然而，为了确保该技术的最佳使用，需要大量的咨询、指导和辅导。此外，必须小心调整 FM 和助听器麦克风的相对增益。
Objective: The primary goal was to determine the benefits and limitations of a remote FM microphone as a hearing aid accessory. A secondary goal was to determine the predictors of aided and FM-assisted speech perception by adults with hearing loss, in quiet and in noise, using methods derived from Articulation Index theory.Design: Twelve adults with mild to severe hearing loss, aged 52 to 85, were fit with behind-the-ear FM hearing aids and used them for a minimum of 2 wk. Phoneme recognition was measured before and after the trial period at several speech levels under three conditions: aided in quiet, aided in spectrally matched noise, and FM-assisted in noise. A single session of counseling, instruction and demonstration was provided before the trial period. Perceived benefit was assessed by questionnaire at the end of the trial period. Measured and perceived benefit were examined in relation to age and pure-tone thresholds.Results: FM-assisted phoneme recognition in noise equaled aided phoneme recognition in quiet. Both were very well predicted by the average pure-tone threshold at 2 and 4 kHz, under a model that assumes Articulation Index (AI) falls with increasing high-frequency threshold at the rate of about 1 percentage point per dB. Aided phoneme recognition in noise was quite well predicted by the same average threshold, under a model that assumes a signal-to-noise ratio of 0 dB reduces Articulation Index to one third of that in quiet. Average perceived benefit was highest for one talker, at a distance, in quiet or in noise. It was lowest for multiple talkers (where the system would be expected to be ineffective) and one close talker in quiet (where the system should be unnecessary). Older subjects and subjects with poorer aided recognition in noise tended to express lower perceived benefit. Many subjects reported that the system was ineffective in reducing background noise. This finding was attributed to use of an "equal gain" criterion in adjusting relative gains via the hearing aid and FM microphones. The single pretrial session of counseling, instruction and demonstration was clearly inadequate for many of the subjects. None expressed an intention to acquire an FM system.Conclusions: The expected benefits of a remote FM microphone in reducing the negative effects of distance and noise, for a single talker, can be demonstrated under both laboratory and field conditions. The effects of hearing loss, noise and FM assistance, on aided phoneme recognition, are well predicted by methods derived from Articulation Index theory. Considerable counseling, instruction and coaching will be needed, however, to ensure optimal use of this technology. In addition, the relative gains via FM and hearing aid microphones must be adjusted with care.